Application of cleaning agents to surfaces to clean soil and stains is well known. Research dealing with exploring how antimicrobial and antifungal agents may be incorporated into cleaning agents for improving their ability to control disease-causing bacteria has also been conducted.
A number of inorganic materials have been shown to exhibit antimicrobial and/or antifungal properties. For example, metals such as silver, copper, zinc, mercury, tin, lead, bismuth, cadmium, chromium and thallium, have been shown to exhibit such properties. While the reasons for this are not yet fully understood, it is thought that ionized forms of these metals interact with thiol containing proteins and DNA thereby preventing the normal biological functions of bacterial or fungal cells.
United States Patent Application Publication No. 20130234263 to Wasan et al. discloses nano-fluids as cleaning compositions for cleaning soiled surfaces, and a method and formulation for their use. The disclosure describes nano-fluids comprising aqueous suspensions of hydrophilic nanoparticles or polymers, useful in soil removal from hard, semi-hard or soft surfaces, and particularly for improved removal of grass and grease stains.
U.S. Pat. No. 7,081,441 to McDonald et al. discloses a composition for cleaning and/or treating surfaces. The composition comprises a nanoparticles component selected from the group consisting of metal oxyhydroxides, modified metal oxyhydroxides and mixtures thereof; a buffer/modifier component; optionally an adjunct ingredient, and the balance of the composition being a polar solvent. According to the disclosure, the metal oxyhydrides in aqueous solution are converted into and maintained as nanoparticulate sized modified metal oxyhydroxides. In one aspect, a dry film results from contacting a surface with the composition that comprises greater than or equal to about 0.05 μg of nanoparticles per cm′ of treated surface.
In the publication entitled “Facile In-Situ Preparation of Poly(Acrylic Acid)-Silver Nanocomposite Thin Films with Highly Dispersed Silver Nanoparticles” (Kim et al.) Mol. Cryst. Liq. Cryst. Vol 568: pp 170-178, 2012, there is disclosed a method of preparing of PAA-Ag nanocomposite thin films with highly dispersed Ag nanoparticles. During the method, silver salts are chemically reacted with acrylic acid, and as a result silver nanoparticles are produced in situ within an acrylic film.
In the publication entitled “In-situ Synthesis of Nano Silver Particles Used in Obtaining of Antimicrobial Film-Forming Materials” (Pica et al.) REV. CHEM. (Bucharest) 63, No. 5, 2012, there is disclosed processes by which silver nanoparticles that are stable in time are obtained for use in formulating antimicrobial coating materials. Chemical synthesis of the silver nanoparticles comprises dissolving and reducing metals salts in a polymer matrix.
U.S. Pat. No. 7,357,949 to Trogolo et al. discloses an encapsulated inorganic antimicrobial additive for controlled release. Microcapsules comprising an antimicrobial agent are encapsulated within a hydrophilic polymer, which is capable of absorbing sufficient water as to enable the action of the encapsulated antimicrobial agent. In this patent, the antimicrobial agent is a zeolite that retains metal ions until they are able to be released via ion exchange.
While it is known to provide surface cleaning compositions that incorporate antimicrobial agents, improvements for prolonged antimicrobial efficacy with cleaning compositions and other surface treatment compositions are desired.